JP3227458B2 - Peeling cleaning method and injection nozzle mechanism used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dirt (cured or uncured state) of containers containing various inks, resin paints, etc., or peeling for regenerating product coatings, or contamination of contaminants due to adhesion of heavy oil or the like. The present invention relates to a peeling cleaning method for peeling and cleaning a surface coating layer of an object to be cleaned by spraying granular sodium bicarbonate, and a spray nozzle mechanism used in the method.

[0002]

BACKGROUND OF THE INVENTION The present inventors have this type of stripping and cleaning technology, already proposed a equipment you exhibit Oite excellent release performance in Japanese Patent Application No. 8-292189. This device is
Paint remaining on the inner surface of the drum, the ink or the like, and sprayed using compressed air bicarbonate powdery therein while rotating the drums <br/> as stripping and cleaning material, automatically released inks, paints, etc. It is a technology that we can do .

[0003]

SUMMARY OF THE INVENTION The above-mentioned peeling and cleaning method and apparatus proposed by the present inventors have a higher cost than conventional manual or chemical dissolution treatments. Although it was possible to significantly improve both in terms of performance and performance, it was not perfect in terms of peeling accuracy, and sufficient peeling performance was obtained for dry-cured paints and inks. Even if it can be demonstrated, it is not dried or paint,
The problem remains that it is difficult to obtain a sufficient peeling effect with the ink or paint as it is immediately after the transfer of the ink.

As a result of research on these problems, uncured paints and inks have elasticity.
It is presumed that the impact force when the powdery sodium bicarbonate was jetted is absorbed, and a sufficient peeling action is not performed. Therefore, initially, in order to increase the injection power, a method of increasing the pressure of the compressed air for injecting sodium bicarbonate was considered, and an experiment was performed by sequentially sliding the pressure from 3, 4, 5, to 10 kg / cm ² . However, the result that the peeling performance was improved by increasing the pressure was not obtained.

[0005] In addition, the amount of sodium bicarbonate used per minute is variously changed around 1 kg (the amount used in view of the profitable cost obtained by the proposed cleaning apparatus), and the particle size (actually, Is not spherical because it is a crystal, but is expressed in this way for convenience).
Experiments were carried out on particle sizes in all ranges, such as those with a large diameter, a large diameter, and a very small diameter powder, with a focus on μ. (See the amount of adhesion) is determined, that is, it is not a decisive factor.

On the other hand, as a washing device, a drum can is laid horizontally, rotated about a horizontal axis, a nozzle enters the drum, and the inside is brought as close to the inner surface of the drum as possible (with an effective distance away). Since it is necessary to clean, the nozzle at the tip of the horizontally extending duct must be bent, but a commercially available ball joint (movable angle range of 30 to 40 degrees) used for this is not sufficient, and
As the bending angle increases, as shown in FIG. 5, the flow path cross-sectional area (L1 → L2) decreases and the flow path resistance extremely increases. There was also a problem that the speed was reduced.

[0007] In view of the problems of the prior art, the present inventors have conducted a number of experiments and, under the conviction that the peeling performance can be achieved by a combined improvement of various factors, have obtained various tests. Through repeated experiments, they have found that the particle size of sodium bicarbonate and the amount and the injection speed of the compressed air for injecting the same have a complex and large causal relationship, and the present invention has been made based on such findings. It is an object of the present invention to provide a peeling cleaning method capable of sufficiently peeling both the hard and soft paints and inks, and an injection nozzle mechanism used in the method.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the method of the present invention is designed such that granular sodium bicarbonate is sprayed on the object to be cleaned together with compressed air to peel and clean the surface coating layer of the object to be cleaned. The method for stripping and cleaning according to any one of claims 1 to 3, wherein the sodium bicarbonate has a substantial particle size of 200 to 350 µm, the pressure of compressed air is 2 kg / cm ^{2 to} 4 kg / cm ² , and 3.5 to 4 liters per gram of the sodium bicarbonate. Of air, the injection speed is 170 m / sec to 335
In this case, a means of injecting at m / sec is taken.

In the present invention, the driving angle α of the sodium bicarbonate to the object to be cleaned is preferably 45 ° to 60 °.

In the present invention, the surface coating layer of the object to be cleaned is a cured or uncured coating film.

[0011] mechanism of the present invention, in order to achieve the above object, the sodium bicarbonate of particle size 200μ to 350 microns, with compressed air pressure is ^{2kg / cm 2 ~4kg / cm 2} , the sodium bicarbonate 1g per 3.5 A conduit through which a mixture of granular sodium bicarbonate and compressed air flows, which is used in a stripping cleaning method in which the surface coating layer of the object to be cleaned is stripped and washed by spraying with a spraying speed of 170 m / sec to 335 m / sec with air of 4 liter to 4 liter. 1, a ball joint 2 connected to the conduit 1, and a nozzle body 3 connected to the ball joint 2, wherein the ball joint 2 has an expansion passage 4 therein. ,
And the extension cover portion 5, and a seal 6 disposed inside of the extension cover portion 5, the nozzle body 3 with respect to the axis of the conduit 1, the angle can be changed in the range of 25 ° to 25 ° It has been configured.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the particle size of sodium bicarbonate is obtained by pulverizing a crystal and is not spherical, but it is used as a method of expressing the size at the upper end for convenience. Things. Further, in the above-described proposed device, water is simultaneously sprayed and ejected (mainly explosion-proof means associated with the generation of static electricity) by ejecting water at the time of injection of sodium bicarbonate, but here, water injection is not required. , May be used as appropriate.

According to the method of the present invention, as can be seen from the graphs of FIGS.
μ to 350μ, pressure is 2kg / cm ^{2 to} 4kg / c
m ² of compressed air was used to achieve an air volume of 3.5-4 liters / g of sodium bicarbonate and 17
By jetting at an injection speed of 0 m / sec to 335 m / sec, the peeling accuracy (residual adhesion amount) of any hard or soft paint or ink was greatly improved. In this case, from the results of the experiment, it was preferable that the driving angle α of the sodium bicarbonate to the object to be cleaned was 45 ° to 60 °.

Further, as an injection nozzle mechanism of the present invention, the ball joint 2 includes an expansion passage 4, an extension cover portion 5, and a seal 6 arranged inside the extension cover portion 5 inside the ball joint 2, The nozzle body 3 is configured to be capable of changing the angle in the range of 25 ° to 25 ° with respect to the axis of the conduit 1, so that the particle size is 200 μ to 35 μm.
The sodium bicarbonate of 0μ, pressure is 2kg ^/ cm 2 ~4kg
170 liters / cm ² of compressed air at 3.5-4 liters of air per gram of sodium bicarbonate.
By jetting at a jet speed of sec to 335 m / sec, the surface coating layer of the object to be cleaned can be peeled and cleaned. Sufficient cleaning accuracy can be improved even in the case of the peeling cleaning in a state that cannot be avoided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a peeling cleaning method according to the present invention and a jet nozzle mechanism used in the method will be described in detail below with reference to the drawings. Here, a description will be given of a drum can in which a soft resin paint that remains more difficult to peel than a cured state remains as an example of the object to be peeled and cleaned in the present invention. However, the entire cleaning device is described in Japanese Patent Application No. 8-29
2189 and Japanese Patent Application No. 8-35432, the detailed description of which is omitted here.

First, sodium bicarbonate has a substantial particle size of 3%.
200μ to 350μ
The range of μ was used. Transport this sodium bicarbonate,
The pressure of the compressed air to be injected is about 3.8 kg / cm ² (G)
3.5 g / g to 4 g / g of the sodium bicarbonate
Air volumes in the liter range were used.

The injection nozzle mechanism has the structure shown in FIG. 3 and includes a conduit 1 through which a mixture of granular sodium bicarbonate and compressed air flows, a ball joint 2 connected to the conduit 1, and a ball joint 2 connected to the conduit 1. Connected nozzle body 3
It is composed of The ball joint 2 includes an extended passage 4 therein, an extended cover portion 5 capable of covering a wide-angle bend, and a seal 6 disposed inside the extended cover portion 5. The angle of the nozzle body 3 with respect to the axis of the conduit 1 can be changed in the range of 25 ° to 25 ° (movable range of 50 °).

An injection speed of 170 m / sec to 335 m / sec is obtained by using this injection nozzle mechanism and by the above-mentioned sodium bicarbonate, air pressure and amount of air used. The injection angle α is 45 ° to 60 ° with respect to the inner surface of the drum to be cleaned.
And the injection distance was 205 mm.

FIG. 1 shows the experimental results, in which the curve shows the relationship of the peeling state (accuracy) in the case of the paint in a state where the viscosity has decreased, that is, in the state where the drying has progressed. This shows a relatively high state, that is, a case of an undried state. From both curves, it can be seen that the hard paint can be sufficiently peeled off at a lower speed than the soft paint.

The vertical axis of this graph indicates the particle size of the peeled paint, and the result is that even when the paint is in an undried state, the spray speed is about 900 km / h (about 250 m / sec) and the powder is almost completely pulverized. was gotten. And the horizontal axis of the graph is the injection speed of the mixed fluid of sodium bicarbonate and air,
The correlation between the two is made clear.

FIG. 2 similarly shows the experimental results, in which the vertical axis of the graph shows the particle size of the re-adhesion of the paint at the end of the peeling.
That is, a value of 0 indicates that complete peeling has occurred and no unpeeled state remains. The horizontal axis of the graph is the amount of air for injecting sodium bicarbonate, and the correlation between the two is made clear. even here,
The curve shows the peeling state (accuracy) relationship in the case where the viscosity of the paint has decreased, that is, in the state where the drying has progressed. The curve shows the case where the viscosity of the paint is relatively high, that is, in the case of the undried state. The relationship between the two is shown.

From this graph, it can be seen that the amount of air used is 400 to 4
From a place exceeding 50 liters, the peeling performance (prevention of re-adhesion) is improved, and in the case of both hard and soft paints,
It can be seen that re-adhesion can be almost completely prevented with about 700 liters. That is, in other words, it can be seen that a sufficient peeling effect can be obtained by using an air amount in the range of 3.5 to 4 liters per gram of sodium bicarbonate.

Therefore, in order to obtain a sufficient pulverized particle size and prevent re-adhesion, at least the sodium bicarbonate has a substantial particle size of 200 to 350 μm and a compressed air pressure of 2 kg / kg .
It has been found that it is necessary to inject at an injection speed of 170 m / sec to 335 m / sec with 3.5 to 4 liters of air per cm ^{2 to 4} kg / cm ² of sodium bicarbonate. In addition, as a result of the experiment,
Although a substantially good peeling performance could be obtained even when the injection speed exceeded 335 m / sec, the injection device was adversely affected by a shock wave as the speed approached the sound speed or exceeded the sound speed. Has been found to be undesirable.

[0024]

According to the method of the present invention, when the paint or the like is peeled off by spraying the powdered sodium bicarbonate powder as a cleaning material with compressed air to remove paint or the like, the peeling performance is as follows: the particle size of sodium bicarbonate, compressed air. pressure, found to be determined by the complex factor that use air quantity and the injection velocity, substantial particle size of the sodium bicarbonate (200 [mu] to 350 microns), the pressure of the compressed air ^{(2kg / cm 2 ~4kg / cm} 2 ), The amount of air per gram of said sodium bicarbonate (3.5 liters
4 liters) and injection speed (170 m / sec-33
5m / sec) to obtain a soft paint that is difficult to peel off,
The separation performance (accuracy) of ink and the like can be dramatically improved.

Further, by the nozzle mechanism of the present invention, a sufficient ejection speed can be secured even when the inner surface of a drum or the like requiring a joint is peeled, and the peeling performance can be improved. Other advantages of the present invention are as described in detail in the above-mentioned Embodiment section and Examples.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of a stripping and cleaning method according to the present invention.

FIG. 2 is a graph showing the results of the peeling and cleaning method according to the present invention.

FIG. 3 is a partial cross-sectional front view of an injection nozzle mechanism used in the stripping cleaning method according to the present invention.

FIG. 4 is a side view of an injection nozzle mechanism used in the peeling and cleaning method according to the present invention.

FIG. 5 Injection nozzles used in the peeling cleaning method according to the prior art
FIG. 3 is a schematic cross-sectional view of a skewing mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conduit 2 Ball joint 3 Nozzle body 4 Expansion passage 5 Extension cover 6 Seal

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B08B 1/00-7/04 B05B 1/00

Claims (4)

(57) [Claims] 1. A stripping / cleaning method comprising spraying granular sodium bicarbonate together with compressed air onto an object to be cleaned to peel and clean a surface coating layer of the object to be cleaned, wherein said sodium bicarbonate has a substantial particle size. 200μ to 350
and mu, the pressure of compressed air at ^{2kg / cm 2 ~4kg / cm 2} ,
The injection speed is from 170 m / sec to 33 with air of 3.5 to 4 liters per gram of the sodium bicarbonate.
A peeling cleaning method, which is sprayed at 5 m / sec. 2. The stripping and cleaning method according to claim 1, wherein the implantation angle α of the sodium bicarbonate with respect to the object to be cleaned is 45 ° to 60 °. 3. The method according to claim 1, wherein the surface coating layer of the object to be cleaned is a cured or uncured coating film. The wherein the particle size of 200μ to 350μ bicarbonate, pressure in the compressed air ^{2kg / cm 2 ~4kg / cm 2} , the sodium bicarbonate 1g per 3.5 liters to 4
With liter of air, 170m / sec to 335m /
A pipe 1 through which a mixture of granular sodium bicarbonate and compressed air flows, and a ball joint 2 connected to the pipe 1 are used in a stripping cleaning method of jetting at a jetting speed of sec to strip and clean the surface coating layer of the object to be cleaned. And a nozzle body 3 connected to the ball joint 2, wherein the ball joint 2 has an expansion passage 4, an extension cover 5, and an inside of the extension cover 5. and a seal 6 disposed in the nozzle body 3 with respect to the axis of the conduit 1, took measures that are configured to be angular change in the scope of 25 ° to 25 °, stripping and cleaning Injection nozzle mechanism used for the method.